Oil baffle for gas turbine fan drive gear system

ABSTRACT

An exemplary turbine engine assembly includes a first shaft that is rotatably driven by a second shaft of a gas turbine engine and a compressor hub driven by the first shaft. The compressor hub is within a compressor section of the gas turbine engine. An epicyclic gear train is driven by the first shaft. A common attachment point secures the first shaft and the compressor hub to the second shaft.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/718,436, which was filed on 5 Mar. 2010. U.S. patent application Ser.No. 12/718,436 is a divisional of U.S. Pat. No. 7,704,178, which wasfiled on 5 Jul. 2006.

BACKGROUND OF THE INVENTION

This disclosure relates to a gas turbine engine architecture.

Gas turbine engines typically employ an epicyclic gear train connectedto a turbine section of the engine, which is used to drive the turbofan. In a typical epicyclic gear train, a sun gear receives rotationalinput from a turbine shaft through a compressor shaft. A carriersupports intermediate gears that surround and mesh with the sun gear. Aring gear surrounds and meshes with the intermediate gears. Inarrangements in which the carrier is fixed against rotation, theintermediate gears are referred to as “star” gears and the ring gear iscoupled to an output shaft that supports the turbo fan. In arrangementsin which the ring gear is fixed against rotation, the intermediate gearsare referred to as “planetary” gears and the carrier is coupled to theoutput shaft that supports the turbo fan.

The epicyclic gear train gears must receive adequate lubrication duringoperation of the turbine engine. To this end, the carrier includes oilspray bars arranged between the intermediate gears and the sun gear tospray oil directly on those gears. Separate oil baffles, which may beintegral with or separate from the carrier, are arranged between theintermediate gears to collect the sprayed oil and retain it in the areaof the intermediate gears for prolonged lubrication before the oil iscollected in a lubricant gutter associated with the ring gear.

Prior art carrier arrangements have required multiple components andcomplicated assembly in order to accommodate the oil baffles. Forexample, one or both of the side walls of the carrier must be assembledaround the intermediate gears resulting in a multi-piece carrier.Furthermore, separate oil spray bars and oil baffles complicate assemblyand increase cost. What is needed is a simplified oil baffle and spraybar arrangement that enables a simpler and less expensive carrierdesign.

SUMMARY OF THE INVENTION

A turbine engine assembly according to an exemplary embodiment of thepresent disclosure includes, among other things, a first shaft that isrotatably driven by a second shaft of a gas turbine engine, and acompressor hub driven by the first shaft. The compressor hub is within acompressor section of the gas turbine engine. An epicyclic gear train isdriven by the first shaft. A common attachment point secures the firstshaft and the compressor hub to the second shaft.

In a further non-limiting embodiment of the foregoing turbine engineassembly, the turbine engine includes an epicyclic gear train that has acarrier and sun gear. Intermediate gears are arranged about, andintermesh with, the sun gear. The intermediate gears are supported bythe carrier.

In a further non-limiting embodiment of either of the foregoing gasturbine engine assemblies, the gas turbine engine includes a bafflesecured to the carrier by a fastening member. The baffle includes alubrication passage near at least one of the sun gear and intermediategears for directing a lubricant on the at least one of the sun gear andintermediate gears.

In a further non-limiting embodiment of any of the foregoing gas turbineengine embodiments, the turbine engine assembly includes a ring gearintermeshing with the intermediate gears and a third shaftinterconnected to the ring gear. The first shaft is interconnected tothe sun gear.

In a further non-limiting embodiment of any of the foregoing gas turbineengine embodiments, the carrier is fixed relative to a housing, thethird shaft drives a turbo fan, and the first shaft supports acompressor hub having compressor blades.

In a further non-limiting embodiment of any of the foregoing gas turbineengine embodiments, the first shaft is a compressor shaft.

In a further non-limiting embodiment of any of the foregoing gas turbineengine embodiments, the epicyclic gear train rotatably drives a thirdshaft.

In a further non-limiting embodiment of any of the foregoing gas turbineengine embodiments, the turbine engine includes roller bearings thatsupport the third shaft.

In a further non-limiting embodiment of any of the foregoing gas turbineengine embodiments, the third shaft is a fan shaft.

In a further non-limiting embodiment of any of the foregoing gas turbineengine embodiments, the second shaft is turbine shaft.

In a further non-limiting embodiment of any of the foregoing gas turbineengine embodiments, the compressor hub includes blades.

In a further non-limiting embodiment of any of the foregoing gas turbineengine embodiments, torque is transferred to the first shaft and thecompressor hub exclusively through the common attachment point.

In a further non-limiting embodiment of any of the foregoing gas turbineengine embodiments, the common attachment point includes a fastener thatextends through an aperture established in flange of the compressor hub,and an aperture established in a flange of the first shaft.

A turbine engine assembly according to an exemplary embodiment of thepresent disclosure includes, among other things, a turbine shaft that isrotated by a turbine of a gas turbine engine, at least one compressorhub that is rotated by the turbine shaft. The at least one compressorhub within a compressor section of the gas turbine engine. The assemblyincludes a compressor shaft that is rotatably driven by the turbineshaft, and a epicyclic gear train that is driven by the compressorshaft. The at least one compressor hub and the compressor shaft arerotatably coupled to the turbine shaft at a common attachment point.

In a further non-limiting embodiment of the foregoing gas turbine engineembodiment, the epicyclic gear train includes a carrier having spacedapart walls with circumferentially spaced mounts interconnecting thewalls. The mounts provide circumferentially spaced apart aperturesbetween the mounts at an outer circumference of the carrier. A sun gearand intermediate gears are arranged about and intermeshing with the sungear. The intermediate gears are supported by the carrier.

In a further non-limiting embodiment of either of the foregoing gasturbine engine embodiments, baffles are arranged between the walls nearthe mounts. The baffles are secured to at least one of the walls and themounts by a fastening element, gear pockets are provided between thebaffles, and the baffles including a lubrication passage terminating atleast one of the gear pockets.

In a further non-limiting embodiment of any of the foregoing gas turbineengine embodiments. The epicyclic gear train rotatably drives a fanshaft. Torque is transferred from the turbine shaft to the compressorshaft and from the turbine shaft to the compressor hub exclusivelythrough the common attachment point.

A method of operating a gas turbine engine according to an exemplaryaspect of the present disclosure includes, among other possible things,applying torque to an epicyclic gear train of a gas turbine engine byrotating a turbine shaft using a turbine section of a gas turbineengine, rotating a compressor hub using the turbine shaft, and rotatinga compressor shaft with the turbine shaft. The compressor shaft isconfigured to rotate an epicyclic gear train. The first shaft is securedto the compressor hub and the compressor shaft at a common attachmentpoint.

In a further non-limiting embodiment of the foregoing method, the methodincludes rotating a fan shaft with the epicyclic gear train.

These and other features of the present invention can be best understoodfrom the following specification and drawings, the following of which isa brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial cross-sectional view of a front portion of a gasturbine engine illustrating a turbo fan, epicyclic gear train and acompressor section.

FIG. 2 is a cross-sectional view of the epicyclic gear train shown inFIG. 1.

FIG. 3 is an end view of the epicyclic gear train taken along line 3-3in FIG. 2 with a pair of star gears shown in phantom in an installationposition.

FIG. 4 is an enlarged view of a portion of the epicyclic gear trainshown in FIG. 3 with a sun gear and star gears shown in phantom.

FIG. 5 is an enlarged view of a portion of the epicyclic gear trainshown in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A portion of a gas turbine engine 10 is shown schematically in FIG. 1.The turbine engine 10 includes a fixed housing 12 that is constructedfrom numerous pieces secured to one another. A compressor section 14having compressor hubs 16 with blades are driven by a turbine shaft (notshown) about an axis A. A turbo fan 18 is supported on a turbo fan shaft20 that is driven by a compressor shaft 24, which supports thecompressor hubs 16, through an epicyclic gear train 22.

In the example arrangement shown, the epicyclic gear train 22 is a stargear train. Of course, the claimed invention also applies to otherepicyclic gear trains such as a planetary arrangement. Referring to FIG.2, the epicyclic gear train 22 includes a sun gear 28 that is connectedto the compressor shaft 24, which provides rotational input, by asplined connection 30.

In the example arrangement shown, the compressor shaft is a two-partshaft having a first shaft 24 a and a second shaft 24 b. The first shaft24 a is connected to the second shaft 24 b via a connection member 31,which is a bolt and nut in this example.

A carrier 34 is fixed to the housing 12 by a torque frame 36. Thecarrier 34 supports intermediate gears (which are star gears 32 in thearrangement shown) that are coupled to the sun gear 28 by meshedinterfaces 26 between the teeth of the sun and star gears 28, 32. A ringgear 38 surrounds the carrier 34 and is coupled to the star gears 32 bymeshed interfaces 44. The ring gear 38, which provides rotationaloutput, is secured to the turbo fan shaft 20 by connection 42.

In one example, the torque frame 36 grounds the carrier 34 to thehousing 12 in a known manner. For example, mounts 53 have apertures 56receiving fingers of the torque frame 36, as shown in FIGS. 2 and 3.Pins 48 that extend through spherical bearings 46 and bushings 52 securethe fingers to the carrier 34. Fasteners 50 retain the pins 48 to thecarrier 34.

The carrier 34 is a unitary structure manufactured from one piece forimproved structural rigidity and ease of assembly. The carrier 34includes spaced apart side walls 60 that are interconnected by themounts 54, which are generally wedge-shaped members, as best shown inFIG. 3. The mounts 54 and side walls 60 are unitary with one another.The mounts 54 have opposing curved surfaces 58 that are in closeproximity to the star gears 32 and generally follow the curvature of theteeth of the star gears 32 so that any oil on the curved surfaces 58will likely find its way to the star gears 32 for additionallubrication.

The mounts 54 are circumferentially spaced about the carrier 34 toprovide apertures 98 through which the star gears 32 extend to engagethe ring gear 38. Returning to FIG. 2, the side walls 60 include holes62 for receiving a journal bearing 64 that supports each of the stargears 32. Each journal bearing 64 is retained within the carrier 34 byretainers 66 fastened to the side walls 60.

Oil baffles 68 are arranged between the side walls 60 near each of themounts 54, best shown in FIG. 2. Referring to FIGS. 4 and 5, the baffles68 include ends 72 that abut the mounts 54, in the example shown. Thebaffles 68 also include opposing curved surfaces 70 arranged in closeproximity to the star gears 28. The curved surfaces 58, 70 arecontiguous with and adjoin one another, in the example shown, andprovide gear pockets 102 that receive the star gears 32. A gear pocket104, which receives the sun gear 28, is also provided between a surface73 on each of the baffles 68 opposite the ends 72.

In one example, one of the side walls 60 includes holes 74 that receivefasteners 76 which secure each of the baffles 68 to the carrier 34. Thebaffles 68 include a lubrication passage provided by a primary passage86 that fluidly communicates with a lubricant distributor 78. Thelubricant distributor 78 is fed oil from a lubricant supply 96. In oneexample, the baffles 68 include openings 82 that receive a tube 80extending through a hole 83 in the side wall 60. Seals 84 seal the tube80 to the opening 82 and lubricant distributor 78. Other tubes 92 havingseals 84 are used to provide oil to an external spray bar 94 throughanother lubrication passage (spray bar passage 93 that extends throughone of the baffles 68). The external spray bar 94 is secured to thecarrier 34 and sprays oil in the vicinity of the sun gear 28 near thesplined connection 30 (shown in FIGS. 2 and 5).

The primary passage 86 is in communication with first and secondpassages 88, 90 that spray oil on the teeth of the sun and star gears28, 32. In the example shown, the first and second passages 88, 90 arearranged ninety degrees from one another.

With the example baffles 68, lubricant distribution is integrated intothe baffle so that separate components are eliminated. The baffles 68can be constructed from a different, lighter weight material than thecarrier 34.

The example carrier 34 can be constructed from one piece, which improvesthe structural integrity of the carrier. A central opening 100 ismachined in at least one of the side walls 60 and provides the gearpocket 104. Gear pockets 102 are machined between the side walls 60 andmounts 54 for each of the star gears 32 and form apertures 98 at anouter circumference of the carrier 34. Referring to FIG. 3, the stargears 32 are inserted into the central opening 100 and moved radiallyoutwardly so that they extend through the apertures 98 and arepreferably in abutment with the mounts 54 (position indicated by dashedlines in FIG. 3). In this position, there is an adequate gap, t, betweenthe teeth of adjacent star gears 32 to accommodate a width, w, of theend 72 of the baffles 68. Once the baffles 68 have been inserted, thestar gears 32 can be repositioned, as shown by the solid lines, and thesun gear 28 can be inserted into the central opening 100 so that itmeshes with the star gears 32. The baffles 68 are secured to the carrier34 using fasteners 76. The tubes 80, 92 can be inserted and the rest ofthe lubricant distribution system can be connected.

Although a preferred embodiment of this invention has been disclosed, aworker of ordinary skill in this art would recognize that certainmodifications would come within the scope of this invention. For thatreason, the following claims should be studied to determine the truescope and content of this invention.

What is claimed is:
 1. A turbine engine assembly comprising: a firstshaft that is rotatably driven by a second shaft of a gas turbineengine; a compressor hub driven by the first shaft, the compressor hubwithin a compressor section of the gas turbine engine; an epicyclic geartrain that is driven by the first shaft; and a common attachment pointthat secures the first shaft and the compressor hub to the second shaft.2. The turbine engine assembly of claim 1, including an epicyclic geartrain having: a carrier, and a sun gear and intermediate gears arrangedabout and intermeshing with the sun gear, the intermediate gearssupported by the carrier.
 3. The turbine engine assembly of claim 2,including a baffle secured to the carrier by a fastening member, thebaffle including a lubrication passage near at least one of the sun gearand intermediate gears for directing lubricant on the at least one ofthe sun gear and intermediate gears.
 4. The turbine engine assembly ofclaim 2, comprising a ring gear intermeshing with the intermediate gearsand a third shaft interconnected to the ring gear, and the first shaftinterconnected to the sun gear.
 5. The turbine engine assembly of claim4, wherein the carrier is fixed relative to a housing, the third shaftdrives a turbo fan, and the first shaft supports a compressor hub havingcompressor blades.
 6. The turbine engine assembly of claim 1, whereinthe first shaft is a compressor shaft.
 7. The turbine engine assembly ofclaim 1, wherein the epicyclic gear train rotatably drives a thirdshaft.
 8. The turbine engine assembly of claim 7, including rollerbearings that support the third shaft.
 9. The turbine engine assembly ofclaim 7, wherein the third shaft is a fan shaft.
 10. The turbine engineassembly of claim 1, wherein the second shaft is turbine shaft.
 11. Theturbine engine assembly of claim 1, wherein the compressor hub includesblades.
 12. The turbine engine assembly of claim 1, wherein torque istransferred to the first shaft and the compressor hub exclusivelythrough the common attachment point.
 13. The turbine engine assembly ofclaim 1, wherein the common attachment point includes a fastener thatextends through an aperture established in flange of the compressor hub,and an aperture established in a flange of the first shaft.
 14. Aturbine engine assembly comprising: a turbine shaft that is rotated by aturbine of a gas turbine engine; at least one compressor hub that isrotated by the turbine shaft, the at least one compressor hub within acompressor section of the gas turbine engine; a compressor shaft that isrotatably driven by the turbine shaft, and a epicyclic gear train thatis driven by the compressor shaft, wherein the at least one compressorhub and the compressor shaft are rotatably coupled to the turbine shaftat a common attachment point.
 15. The turbine engine of claim 14,wherein the epicyclic gear train includes a carrier having spaced apartwalls with circumferentially spaced mounts interconnecting the walls,the mounts providing circumferentially spaced apart apertures betweenthe mounts at an outer circumference of the carrier, and a sun gear andintermediate gears arranged about and intermeshing with the sun gear,the intermediate gears supported by the carrier.
 16. The turbine engineassembly of claim 15, including baffles arranged between the walls nearthe mounts, the baffles secured to at least one of the walls and themounts by a fastening element, gear pockets provided between thebaffles, and the baffles including a lubrication passage terminating atleast one of the gear pockets.
 17. The turbine engine assembly of claim14, wherein the epicyclic gear train rotatably drives a fan shaft. 18.The turbine engine assembly of claim 14, wherein torque is transferredfrom the turbine shaft to the compressor shaft and from the turbineshaft to the compressor hub exclusively through the common attachmentpoint.
 19. A method of applying torque to an epicyclic gear train of agas turbine engine comprising: a) rotating a turbine shaft using aturbine section of a gas turbine engine; b) rotating a compressor hubusing the turbine shaft; and c) rotating a compressor shaft with theturbine shaft, the compressor shaft configured to rotate an epicyclicgear train, wherein the first shaft is secured to the compressor hub andthe compressor shaft at a common attachment point.
 20. The method ofclaim 19 including rotating a fan shaft with the epicyclic gear train.21. A turbine engine assembly comprising: a compressor hub and atwo-part compressor shaft, containing an aft part and a forward part,the forward part connected to an epicyclical gear train and the aft partdriven by an engine core shaft; wherein a compressor hub and two-partshaft are connected at a common joint.
 22. The turbine engine assemblyof claim 21, wherein the engine core shaft is a turbine section shaft.23. The turbine engine assembly of claim 21, wherein the common joint isconfigured to transfer torque from the aft part to both the forward partand the compressor hub.
 24. The turbine engine assembly of claim 23,wherein torque is transferred from the aft part to both the forward partand the compressor hub exclusively through the common joint.